The Kempen system is a dairy feeding system in which diet is provided in the form of a compound feed (CF) and hay offered ad libitum. Ad libitum access to CF and hay allows cows in this system to achieve a high DM intake (DMI). Out of physiological concerns, the voluntary hay intake could be increased and the consumption pattern of CF could be manipulated to maintain proper rumen functioning and health. This study investigated the effects of an artificial hay aroma and CF formulation on feed intake pattern, rumen function and milk production in mid- to late-lactating dairy cows. Twenty Holstein-Friesian cows were assigned to four treatments in a 4 × 4 Latin square design. Diet consisted of CF and grass hay (GH), fed separately, and both offered ad libitum, although CF supply was restricted in maximum meal size and speed of supply by an electronic system. Treatments were the combination of two CF formulations - high in starch (CHS) and fibre (CHF); and two GH - untreated (UGH) and the same hay treated with an artificial aroma (TGH). Meal criteria were determined using three-population Gaussian-Gaussian-Weibull density functions. No GH × CF interaction effects on feed intake pattern characteristics were found. Total DMI and CF intake, but not GH intake, were greater (P < 0.01) in TGH treatment, and feed intake was not affected by type of CF. Total visits to feeders per day, visits to the GH feeder, visits to the CF feeder and CF eating time (all P < 0.01) were significantly greater in cows fed with TGH. Meal frequency, meal size and meal duration were unaffected by treatments. Cows fed CHF had a greater milk fat (P = 0.02), milk urea content (P < 0.01) and a greater milk fat yield (P < 0.01). Cows fed TGH had a greater milk lactose content and lactose yield (P < 0.05), and milk urea content (P < 0.01). Cows fed TGH had smaller molar proportions of acetic acid and greater molar proportions of propionic acid compared with UGH. In conclusion, treatment of GH with an artificial aroma increased CF intake and total DMI, but did not affect hay intake. Additionally, GH treatment increased the frequency of visits to both feeders, and affected rumen volatile fatty acid profile. Type of CF did not affect meal patterns, ruminal pH, nor fermentation profiles.

中文翻译：

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人工干草香气和复合饲料配方对泌乳奶牛的采食方式，瘤胃功能和产奶量的影响。

Kempen系统是一种乳制品喂养系统，其中以复合饲料（CF）的形式提供饮食，并随意提供干草。随意获取CF和干草可使该系统中的奶牛获得较高的DM摄入量（DMI）。出于生理考虑，可以增加干草的自愿摄入量，并且可以控制CF的消费方式，以维持瘤胃功能和健康。这项研究调查了人工干草味和CF配方对泌乳中期至晚期的奶牛的采食方式，瘤胃功能和产奶量的影响。在4×4拉丁方形设计中，将20头Holstein-Friesian奶牛分配给了四种处理方法。饮食由CF和干草（GH）组成，分别喂养，并且都可以随意采食，尽管通过电子系统限制了CF的供应量，但最大膳食量和供应速度受到限制。处理是两种CF配方的组合-高淀粉（CHS）和纤维（CHF）；和两个未经处理的GH（UGH），以及用人工香气（TGH）处理的同一干草。使用三人口高斯-高斯-威布尔密度函数确定餐食标准。没有发现GH×CF相互作用对采食模式特征的影响。在TGH处理中，DMI和CF的总摄入量而不是GH的摄入量更大（P <0.01），并且饲料的摄入量不受CF类型的影响。TGH饲喂的奶牛每天的总进食量，GH的进食量，CF的进食量和CF的进食时间（均P <0.01）显着增加。进餐频率，进餐量和进餐时间不受治疗的影响。用CHF喂养的奶牛的乳脂含量更高（P = 0.02），乳脲含量（P <0.01），乳脂产量也更高（P <0.01）。饲喂TGH的奶牛的牛奶乳糖含量和乳糖产量更高（P <0.05），而牛奶尿素含量更高（P <0.01）。与UGH相比，饲喂TGH的母牛的乙酸摩尔比例较小，丙酸摩尔比例较大。总之，用人工香气处理GH可增加CF摄入量和总DMI，但不影响干草摄入量。此外，GH处理增加了两次进食的次数，并影响了瘤胃挥发性脂肪酸谱。CF的类型不影响进餐模式，瘤胃pH值或发酵曲线。饲喂TGH的奶牛的牛奶乳糖含量和乳糖产量更高（P <0.05），而牛奶尿素含量更高（P <0.01）。与UGH相比，饲喂TGH的母牛的乙酸摩尔比例较小，丙酸摩尔比例较大。总之，用人工香气处理GH可增加CF摄入量和总DMI，但不影响干草摄入量。此外，GH处理增加了两次进食的次数，并影响了瘤胃挥发性脂肪酸谱。CF的类型不影响进餐模式，瘤胃pH值或发酵曲线。饲喂TGH的奶牛的牛奶乳糖含量和乳糖产量更高（P <0.05），而牛奶尿素含量更高（P <0.01）。与UGH相比，饲喂TGH的母牛的乙酸摩尔比例较小，丙酸摩尔比例较大。总之，用人工香气处理GH可增加CF摄入量和总DMI，但不影响干草摄入量。此外，GH处理增加了两次进食的次数，并影响了瘤胃挥发性脂肪酸谱。CF的类型不影响进餐模式，瘤胃pH值或发酵曲线。但没有影响干草的摄入。此外，GH处理增加了两次进食的次数，并影响了瘤胃挥发性脂肪酸谱。CF的类型不影响进餐模式，瘤胃pH值或发酵曲线。但没有影响干草的摄入。此外，GH处理增加了两次进食的次数，并影响了瘤胃挥发性脂肪酸谱。CF的类型不影响进餐模式，瘤胃pH值或发酵曲线。